Arrangement for manufacturing of screws



June 25, 1929. I o. L. swENosEN ARRANGBIENT FOR MANUFACTURING 0F SCREWSFiled Jan. 14, 192'1 lud,

INVENTOR;

u Mtorn'ey.

Patented June 25, 1929.

UNITED STATES PATENT OFFICE.

.ARRANGEMENT FOR MANUFACTURING OF SCREWS.

Application filed January 14, 1927, Serial This invention relates to adevice for manufacturing screws in which an arresting means is insertedinto the slot in the head of the screw blank to be t-hreaded in the wellknown manner so as to prevent slippage of the screw while it is beingthreaded. As the arresting means is stationary, the screw blank must beturned until the slot in its head is in alignment with said arrestingmeans so that said arresting means may enter said slot.

The object of this invention is to provide means for turning the screwblank in such a manner that, when the rotation of the screw blank isstopped by the entrance of said screw arresting means into said slot,the screw rtating means will not exert any substantial torsional forceon said screw blank.

This object is accomplished by providing a chuck for ripping said blank,said chuck being carried by a rotating spindle. This spindle isconnected to the source of power by a friction clutch' which slips whensaid Screw arresting means enters said slot. Furthermore said chuck isot' the resilient type and is also capable ot slipping when theresistance to its grasping action becomes greater than the graspingstrength of its jaws.

Further objects and advantages will appear from the accompanyingdetailed description ot' the drawing, in which Figure 1 is a side viewof the device partly in section, and

Figure 2 is a detail ot.' the driving niechanism for the chuck.

Referring to the drawings in detail 1 is a blank to be threaded which isinserted in the chuck 13 by any desirable method which is mounted on theend of a spindle 2O on which is mounted a friction disc 16 which isdriven by a disc cooperating therewith and which in turn is connected toa source of power by a chain or other transmission means.

It is obvious that when the rotation of the chuck spindle is stopped aslippage will occur between discs and 16 whereby damage to the head oithe screw blank and the screw arresting means will be avoided.

The chuck 13 is made up ot jaws which are radially slidable pins 13premed inwardly by peripheral springs 19 whereby they resiliently graspthe screw blank and slip thereon it the pressure resisting theirgrasping No. 161,075, and in Sweden May 28, 1926.

action is greater than the strength of the peripheral spring.

Inside the spindle carrying chuck 13 is a 55 slidable rod 13 adjacentthe free end of which is a lever 2 whereby said rod may be pushedoutwardly to eject the blanks from the chuck 13.

In Figure 1, a conventional chuck 17 iS 60 illustrated, having a taperedend 18 to engage the screw head slot. It will be understood that anyspecific type chuck structure may be utilized for the purpose ofengaging the head of the blank 1 during operation oi' 65 the chuck 13,and that the type of chuck 17 used, in no way affects the presentinvention as claimed.

Having now described the object of my invention and a practicalembodiment of the same, what I claim is:

1. In a machine for manufacturing screws in which arresting means engagethe slot in the head of a screw blank to prevent the slippage of saidblank during the threading J operation, means to bring said arrestingmeans into engagement with said slot comprising a resilient chuck forgrasping the shank of said blank, means to rot-ate said chuck and afriction clutch connecting said rotating means with a source of powerWhereby destruction oil said blank and said arresting means afterengagement is prevented.

2. In a machine for manufacturing screws in which arresting means engagethe slot in the head of the screw blank to prevent the slippage of saidblank during the threading operation, means to bring said arrestingmeans into engagement with said slot com prising a resilient chuck forgrasping the shank of said blank, means to rotate said chuck, a frictionclutch connecting said rotating means with a source of power wherebydestru'ction of said blank and said arresting means after engagement isprevented, and means for ejecting said blank from said chuck afterengagement of said arresting means and said slot.

3. In a machine for manufacturing screws in which arresting means engagethe slot in the head of a screw blank to prevent t-he slippage of saidblank during the threading operation, means to bring said arrestingmeans into engagement with said slot comprising a chuck for grasping theshank of said blank havingjaws comprising radially slidable pins pressedinwardly by a peripheral spring, said chuck being mounted yOna hollowspindle, means for rotating' said spindle comprising,` a friet-ionclutch between said spindle and a source of energy, a rod Slidablymounted in said hollow spindle in alignment with the space between thejaws of said chuck and a lever at the free end of said rod 'for moving10 it into said chuck to eject the bla-nk from eaid chuck afterengagement of said arresting ine-ans with said slot.

In testimony whereoil I have affixed my signature.

vDAVID LEONARD SVVENDSN.

